A preliminary report on clays oe elorida 
185 
Chemical Analysis of JV. J. McLaughlin Clays, A. M. Henry, Analyst. 
Lab. Numbers. 
0-19 0-72 
Silica (Si0 2 ) ..... 54.95 34.55 
Iron and Aluminum oxides.... 11.54 5.75 
Calcium oxide (CaO) . 9.10 24.40 
Magnesium oxide (MgO) . 5.54 6.63 
Moisture at 100°C. 4.37 1.70 
Both samples contain considerable organic matter. 
85.50 73.03 
The Bartow clay occurs in the northeastern part of the county. 
(For a discussion of Bartow clay see Polk County, page 195.) This 
area, however, is not accessible to transportation. 
Fuller’s earth occurs in the Alum Bluff formation and is mined at 
Ellenton on the north side of the Manatee River. 
MARION COUNTY 
Marion County is situated in the central part of the peninsula. Its 
western half is underlain chiefly by the Ocala and the eastern half by the 
Alum Bluff formation. Numerous outliers of the Alum Bluff and 
Alachua formations are found in the Ocala formation. The eastern part 
of the county extends to Lake George in the St. Johns River valley and 
includes flood-plain deposits. Marion County is partly in the Lake 
Region, and numerous lacustrine deposits, chiefly in sink-holes, are 
found locally. 
Residual clays from the Ocala limestone are of common occurrence 
but few of them are of commercial importance. The losses from warp¬ 
ing and cracking in drying and firing these clays are often excessive. In 
the northwestern part of the county, just across the county line from 
Williston in Levy County, are some residual clays having the same prop¬ 
erties as the Williston School clay. (See Levy County, page 180.) Cal¬ 
careous residual clays are found near Dunnellon, Summerfield, and 
Kendrick. 
Sedimentary clays underlie extensive areas in the eastern part of 
the county. One of these is found in the region about Burbank. Here 
the clay is over eighteen feet deep and overlain by about one foot of 
sandy soil. The exact depth of the clay is not known. 
This clay is red-burning, has good plasticity, works well and dries 
without difficulty. It may be used for common brick, hollow-block ware, 
